Structural element



11, 1942- I G. T. GERLACH ET L 2,292,372

STRUCTURAL ELEMENT Filed July 28, 1941 Patented Aug. 11, 1942 STRUCTURAL ELEMENT Glendon '1. Gerlach, Peter Altman, and Alfred S.

Kos, Detroit, Mich, assignors to Vultee Aircraft, Ina, Vultee Field, CaliL, a corporation of? Delaware Application July 28, 1941, Serial No. 404,380

Claims.

The invention relates to metal elements such as bulkheads.

One object of the invention is to provide a bull:- head which comprises expandedmetal and a thin skin-forming sheet, the expanded metal having arched deformed portions and strips spaced from the sheet and connecting the arched portions so the bulkhead will have a high strength-weight ratio and transverse rigidity and which can be substituted for elements of light weight metal, such as aluminum.

Other objects of the invention will appear from the detailed description.

The invention consists in the several novel fea tures which are hereinafter set forth and are more particularly defined by claims at theconclusion hereof.

In the drawingzFig. 1 is a face view of a bulkhead embodying the invention. Fig. 2 is a section on line 22 of Fig. 1. Fig. 3 is a face view of a portion of the bulkhead on a somewhat larger scale. Fig. 4 is a section taken on line 1-6 of Fig. 3. Fig. 5 is a view of a modified form of the invention.

The invention is exemplified in a bulkhead of oval contour which maybe used in airplane structures. The bulkhead comprises a rim l0, angular in cross-section and bent to the desired contour of the margin of the bulkhead. A sheet H of thin skin-forming metal, such as steel, has its margin spot-welded to one of the flanges of the rim l0. Diamond-mesh expanded metal I! is spot-welded at spaced points throughout the entire area of the sheet H. The expanded metal is of the diamond-mesh type which has been flattened so that the faces of the bonds and strands will be coplaner and comprises diagonal strands ll joined by bonds l3. The strands of the flattened expanded metal are bent, before said metal is spot-welded to sheet ii, to form a succession of rows of arched or substantially V- shaped portions 15. This results in, coplaner faces iii in the alternating rows of bonds which fit against oneface of the sheet H. The faces N of the intermediate rows of bonds R3 are coplaner and spaced transversely away from the sheet. lhe rows of arched portions extend entirely across the sheet. The faces Hi or" alternate rows of bonds i3 are spot-welded to the sheet, as at Iii. channelled strips comprise a web H which fits the faces I3 of the bonds and inclined divergent flanges is which fit against the outer portions of the strands in alternating rows of arched portions I5. These strips are spotwelded to the bonds of the expanded metal as at 29.

In fabricating the bulkhead the strips H are welded to the faces 63 of the bonds before the faces 83 are welded to the sheet "I.

In practice, it has been found that a bulkhead composed of a sheet .007" in thickness and diamond-mesh expanded metal with a long axis of 3.25 and a short axis 1.56" (before the arched portions are formed therein) and the strands approximately .050" in thickness, without regard to the reinforcement formed by the arched portions of the expanded metal and the ridge-strips, has greater transverse strength under compression than aluminum .032" in thickness and that the weight of the bulkhead will be no greater than when formed of aluminum. The arched portions of the expanded metal and the strips provide adequate transverse strength for predetermined loads;

The strips may extend across transverse rows of the arched portions of the expanded metal. as illustrated in Fig. 3, or may extend across longitudinal rows of the arched portions, as illustrated in Fig. 5.

The invention exemplifies a structural element. such as a bulkhead, having a high strengthweight ratio and in which a thin skin-forming sheet is adequately reinforced to resist transvers stresses or deflections.

The invention is not to be understood as restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

'.Having thus described the invention, what we claim as new and desire to secure by Letters Patent is:

1. A structural element comprising a thin skinforming sheet, expanded metal having a substantially continuous succession of rows of arched portions between alternate rows of the bonds oi the expanded metal extending transversely away from the sheet, the portions between the arched portions being bonded to the sheet, and strips extending across and bonded to the rows of the arched portions of the expanded metal and spaced transversely from the sheet.

2. A structural element comprising a thin skinforining sheet, flattened expanded metal having a substantially continuous succession ofrows of arched portions between alternate rows of the bonds of the expanded metal extending transversely away from the sheet, the portions between the arched portions being bonded to one face of the sheet, strips extending across and bonded to the rows of the arched portions of the expanded metal and spaced transversely from the sheet, and a rim secured to the other face of the sheet.

3. A structural element comprising a thin skinforming sheet, flattened expanded metal having a substantially continuous succession of rows of arched portions between alternate rows of the bonds of the expanded metal extending transversely away from the sheet, the portions between the arched portions being bonded to the sheet, and strips extending across and bonded to the rows of the arched portions of the expanded metal and spaced transversely from the sheet, said strips having divergent flanges extending toward the sheet.

4. A structural element comprising a thin skinforming sheet of metal and diamond-mesh expanded metal having a substantially continuous succession of rows of arched portions with the bonds in alternate rows coplaner and bonded to the sheet and the bonds at intermediate rows coplaner and spaced apart transversely from the sheet, and strips extending along and welded to the bonds in the intermediate rows.

5. A structural element comprising a thin skin- Iorming sheet of metal and diamond-mesh expanded metal having a substantially continuous succession of rows of arched portions with the bonds in alternate rows coplaner and bonded to the sheet and the bonds 0! intermediate rows coplaner and spaced apart transversely from the sheet, and strips extending along the welded to the bonds in the intermediate rows, the strips having flanges extending toward the sheet.

GLENDON T. GERLACH. PETER ALTNIAN. ALFRED S. KOS. 

